Apple self-driving car sensors appear on Twitter video

It's difficult to keep a self-driving car project secret when testing on public roads, and doubly so in the San Francisco Bay Area, where a surplus of engineers will spot the things and tweet about them. Such seems to be the case with a tweet that appears to show video of the sensor array atop Apple's very secret self-driving test vehicle.

The video was captured and posted to Twitter by MacCallister Higgins, co-founder of self-driving car company Voyage. It shows a sensor array atop the roof of a Lexus RX, the type of vehicle Apple is using to test its self-driving car platform. In a direct message on Twitter, Higgins said that he took the video at the intersection of De La Cruz and the Central Expressway in Sunnyvale, and he is convinced that it was one of Apple's cars.

Self-driving cars are being developed by a wide range of companies, from automakers to tier 1 equipment suppliers to big technology players, such as Google and Apple. The technology could reduce or eliminate the over 1 million deaths caused by cars around the world each year. Many self-driving cars, manned by a human safety driver, are currently being tested on public roads, and they are expected to enter regular service as robo-taxis or private cars in 2020.

Typically, self-driving cars being tested today use an array of sensors that include radar, lidar and cameras. A computer processes this sensor data to build a real-time virtual version of the world outside. The computer makes driving decisions based on the safe paths it "sees." The array atop the Apple car seems to show a similar set of sensors.

The fact that this sensor array shows white plastic casings around much of its structure suggests Apple may be readying it for a public unveiling.

Editor's note: This article has been updated to include a response from MacCallister Higgins about the location where the video was taken.